Gill Marcus was born in 1949 to parents who were active members of the African National Congress (ANC). She grew up in Johannesburg, where she attended Barnato Park High School for Girls.
Marcus went on to study for a Bachelor of Commerce (BCom) degree at the University of Witwatersrand (Wits), but then decided to study Industrial Psychology, a degree she completed in London when her parents decided to leave South Africa in 1969.
She resumed work with the ANC in 1970 when she worked for the party’s Department of Information and by 1976 she had become the editor of the ANC’s weekly bulletin, the Weekly News Briefing.
Marcus later went into exile where she spent her time clipping South African newspapers for the ANC and discussing radical politics. On her return from exile in 1990, after the unbanning of the ANC and other political organisations, Gill took up a post in the ANC's Department of Information and Publicity where she quickly became one of the ANC's more prominent voices.
In 1991, she was elected into the ANC’s National Executive Committee and was co-opted to the national working committee. Before the 1994 elections, she trained ANC media workers and voter educators and accompanied Nelson Mandela on his election campaign into the provinces. Gill played a leading role in determining media policies for the ANC in the run up to the 1994 elections.
After the election, she was elected to parliament and quickly established a reputation for her efficiency in her position as chairperson of the parliamentary joint Finance committee. This is a position she held from June 1994 until June 1996 when she was appointed Deputy Minister of Finance.
On the 1st of July 1999, Gill was appointed as Deputy Governor of the South African Reserve Bank, the first woman to hold such a position. Marcus has also held senior positions in the private sector, including serving on the boards of the mining company, Western Areas and the Absa Group.
Marcus’ more recent achievements have included being made professor of policy, leadership and gender studies at the Gordon Institute of Business Science (2005) and governor of the Reserve Bank (2009).